Tarsonemus Mite Female

This specimen was found on a tapelift from a home in Cleveland, Ohio. There was a very significant
population of these mites in this home. The female can be distinguished from the male by its slightly larger size and by its
very thin, long, fourth pair of legs. These are just visible in this photograph directed straight back over the last third
of the mites body in the upper part of the image. The head of the mite is facing down to the left. The mite is surrounded
by fungal spores.

Mites or their debris are found in indoor environments frequently. They all tend to be small ranging from about 40
micrometers to about a millimeter in largest dimension. They lay eggs and then develop through a number of intermediate
stages. The adult mite has 8 legs but the intermediate stages may have 2 to 8 legs, depending on the species and the stage.
All mites require a relative humidity above 50% but they will often occupy cooler parts of a home where the relative
humidity is naturally higher. They will also inhabit bedding and clothing where the relative humdity is elevated due to
the presence of the human body. Their prefered food varies by species. Many of them will survive on skin flakes.

Significance in the Environment:

There are over 124 different types of mites found in homes. Most of these are associated with allergies or asthma. The
standard tests for mite allergen can only detect 2 of the 124 mites that may be present. The collection efficiency of
a vacuum for even the 2 mites that could be detected is estimated at about 1%. Minor flucuation in that efficiency result
in variations of a factor of 20X (2000%). Part of this variation is due to the fact that the mite allergen is often
concentrated in a few large particles. The allergen of a few fragments would be swamped by the allergen associated with
one whole mite. Tapelifts of settled dusts in homes have been much more consistent in detecting mite problems.

Characteristic Features:

Tarsonemus mites are rather small compared to many other mites found in homes. The main part of the body excluding the
mouth parts, the idiosoma, in the female is typically over 100 micrometers long and clearly divided into a forward section,
the proterosoma, that contains the first two pairs of legs and mouth parts, and a posterior section, the hysterosoma, that
includes the last two pairs of legs. The female Tarsonemus mite can be distinguished from the male by its very thin fourth
pair of legs that terminate in two long setae.